Umno is unfazed about defectors from their party joining the newly formed Parti Pribumi Bersatu Malaysia (Bersatu), said Umno secretary-general Tengku Adnan Tengku Mansor.

"We're not worried. Ezam Mohd Nor (joining Bersatu), we're not worried," he told reporters during a pitstop for the Putrajaya Community Ride at his house in Putrajaya today.

Ezam Mohd Nor is a former senator who announced his intention to quit Umno earlier this month and on Thursday said he had applied to join Bersatu.

Tengku Mansor was asked about a group of Umno Youth leaders who are reportedly set to announce their defection to Bersatu later today at an event in Ampang.

The group is led by former exco member Mohd Rafiq Naizamohideen, who had previously decried what he described as "selective" action after he was suspended for purportedly attempting to sabotage Prime Minister Najib Abdul Razak and Malacca Chief Minister Idris Haron.

Tengku Adnan said it was the Umno Youth leaders' right to leave the party and join whichever party they choose.

"Well, it is his right. You know that the PPBM (Bersatu), Parti Pecah Melayu Berhad, Parti Pemecah Melayu Bersatu or whatever you call it, these are people who are maybe discontent, who can't achieve whatever they want in Umno.

"(So) they leave the party. But in the end, the rakyat know it is BN, which is a multiracial coalition, that will provide and will walk the talk and serve the rakyat for the betterment of the country," he said.

Bersatu is a splinter party formed by former prime minister Dr Mahathir Mohamad, and sacked former deputy prime minister Muhyiddin Yassin as well as former Kedah menteri besar Mukhriz Mahathir.

They had all been vocal critics of Najib and his brainchild 1MDB since last year.